GPSRINEX(1)		      GPSD Documentation		   GPSRINEX(1)

NAME
       gpsrinex - Read data from gpsd convert to RINEX3 and save to a file.

SYNOPSIS
       gpsrinex [OPTIONS] [server[:port[:device]]]

       gpsrinex -h

       gpsrinex -V

DESCRIPTION
       gpsrinex is a tool to connect to gpsd and output the received raw
       measurements as a RINEX 3 observation file. This is useful for sending
       raw measurements (pseudorange and carrierphase) from gpsd to a Precise
       Point Positioning (PPP) program or service.

       gpsrinex does not require root privileges, but may be run as root.
       Some of the examples in this file may not work when run under sudo.  It
       can be run concurrently with other tools connecting to a local or
       remote gpsd without causing problems.

       gpsrinex needs the GNSS receiver to be sending raw measurements to
       gpsd.  Only a few GNSS have this capability. In addition, the gpsd
       driver for that GNSS must support raw mode. Currently only the u-blox
       driver has this support. Only a few u-blox 8 and 9 receivers implement
       the required UBX-RXM-RAWX message. The NEO-M8T is known to work, but
       requires configuration with ubxtool.

       Before using ubxtool be sure to set the UBXOPTS environment variable
       with the correct protocol version for your u-blox receiver. If your
       protocol version is 32.00, you would do this:

	   export UBXOPTS="-P 32.00"

       RINEX has its own definitions and abbreviations. Be sure to consult
       their documentation. An observation file (.obs) contains data sets,
       called epochs, that contain the pseudorange and carrierphase for each
       satellite seen.

       gpsrinex by default will acquire 20 epochs spaced apart by 30 seconds.
       That will take 10 minutes to complete. Most users consider the 30
       second interval to be optimal. Many PPP programs require at least 1 or
       2 hours data, but no more than 24 or 48 hours of data. Most users
       consider 4 to 6 hours of data as a minimum for good accuracy.
       Additional hours will not yield much improvement.

       The output will consist of one RINEX 3 observation file that is ready
       to be read by your PPP program. The default filename will be in the
       form: gpsrinexYYYYDDDDHHMM.obs. You can override this filename with the
       -f option.

       Optionally a server, TCP/IP port number and remote device can be given.
       If omitted, gpsrinex connects to localhost on the default port (2947)
       and watches all devices opened by gpsd.

OPTIONS
       -?, -h, --help
	   Print a usage message and exit.

       -D LVL, -debug LVL
	   Set debug level to LVL.

       -f OUTFILE, --fileout OUTFILE
	   save RINEX into FILE.

       -F INFILE, --filein INFILE
	   Read GPS JSON from file, not from a live gpsd.

       -i SECS, --interval SECS
	   wait [interval] seconds between epochs. The interval can be
	   specified to the millisecond. OPUS accepts intervals of 1, 2, 3, 5,
	   10, 15 or,30 seconds. OPUS then reduces the data to 30 second
	   intervals. Default is 30.000.

       -n COUNT, --count COUNT
	   Causes COUNT epochs to be output. OPUS requires a minimum af 15
	   minutes, and a maximum of 48 hours, of data.

       -V, --version
	   makes gpsrinex print its version and exit.

       The following options set strings that are placed in the generated
       RINEX 3 obs file. They do not change how gpsrinex computes anything.

       --agency AGENCY
	   The name of the agency creating the current file.

       --ant_num NUMBER
	   The antenna serial number.

       --ant_type TYPE
	   The antenna type.

       --marker_name NAME
	   The marker name.

       --marker_type TYPE
	   The marker type

       --observer OBSERVER
	   The name of the observer (you).

       --rec_num NUM
	   The receiver serial number.

       --rec_type TYPE
	   The receiver type.

       --rec_vers VERS
	   The receiver version.

       The following options set floating point numbers that are placed in the
       generated RINEX 3 obs file. They do not change how gpsrinex computes
       anything.

       --ant_e EASTING
	   The antenna easting from marker in meters.

       --ant_h HEIGHT
	   The antenna height from marker in meters.

       --ant_n NORTHING
	   The antenna northing from marker in meters.

ARGUMENTS
       By default, clients collect data from the local gpsd daemon running on
       localhost, using the default GPSD port 2947. The optional argument to
       any client may override this behavior: [server[:port[:device]]]

       For further explanation, and examples, see the ARGUMENTS section in the
       gps(1) man page

EXAMPLES
       Example 1:

       Create a 4 hour .obs file. With a running gpsd accessible on the
       localhost do all of the following, in order. Order matters.

       The raw measurement messages are long. Be sure your serial port speed
       is high enough:

	   gpsctl -s 115200

       Disable all NMEA messages, and enable binary messages:

	   ubxtool -d NMEA
	   ubxtool -e BINARY

       The NEO-M8N will only reliably output raw measurements when only the
       GPS and QZSS constellations are enabled. If your PPP service can use
       GLONASS, then enable that as well. Be sure to disable, before enable,
       so as not to momentarily have too many constellations selected.
       ubxtool, as recommended by u-blox, enables the QZSS constellation in
       tandem with GPS. Disable all constellations, except GPS (and QZSS):

	   ubxtool -d BEIDOU
	   ubxtool -d GALILEO
	   ubxtool -d GLONASS
	   ubxtool -d SBAS
	   ubxtool -e GPS

       Verify the constellations enabled:

	   ubxtool -p CFG-GNSS

       Enable the good stuff, the raw measurement messages:

	   ubxtool -e RAWX

       Verify raw data messages are being sent:

	   ubxtool | fgrep RAWX

       You should see this output:

	   UBX-RXM-RAWX:
	   UBX-RXM-RAWX:

       Collect 4 hours of samples at 30 second intervals, save the RINEX 3
       observations in the file today.obs:

	   gpsrinex -i 30 -n 480 -f today.obs

       Wait 4 hours. Enjoy a meal, or do some exercise. When gpsrinex
       finishes, upload the file today.obs to your favorite PPP service.

       Example 2:

       Collect raw measurement data from a remote gpsd. Then process it later
       with gpsrinex and gpsprof.

       Ensure the receiver is configured properly, as shown in Example 1.

       Grab 4 hours of raw live data from remote gpsd at 10.168.1.2:

	   gpspipe -x 14400 -R 10.168.1.2 > 4h-raw.ubx

       When gpspipe is complete, the file 4h-raw.ubx will contain 4 hours of
       raw UBX binary message.	Convert that raw data in gpsd JSON with
       gpsdecode:

	   gpsdecode < 4h-raw.ubx > 4h-raw.json

       The file 4h-raw.json will now contain the data encoded as gpsd JSON.
       Use gpsrinex to read that file and create a RINEX file:

	   gpsrinex -F 4h-raw.json

       The RINEX file will be in the current directory with the file name
       like: gpsrinexYYYYjjjHHMMSS.obs

       You can now use the JSON	 file to generate a polar plot of the used
       satellites:

	   gpsprof -f polarused -T jpeg -r < 4h-raw.json > 4h-raw.plot
	   gnuplot < 4h-raw.plot > 4h-raw.png

       Use the image viewer of your choice to view your skyview in 4h-raw.png

RETURN VALUES
       0
	   on success.

       1
	   on failure

SEE ALSO
       One service known to work with gbsrinex output is at:
       <https://webapp.geod.nrcan.gc.ca/geod/tools-outils/ppp.php>

       OPUS requires 2 frequency observation files.
       <https://www.ngs.noaa.gov/OPUS/>

       The curious can find the RINEX 3.04 format described here:
       <ftp://igs.org/pub/data/format/rinex304.pdf>

       gpsd(8), gps(1), gpsprof(1), gpsfake(1). ubxtool(1), gpsd_json(5)

RESOURCES
       Project web site:  <https://gpsd.io/>

COPYING
       This file is Copyright 2013 by the GPSD project
       SPDX-License-Identifier: BSD-2-clause

AUTHOR
       Gary E. Miller

GPSD, Version 3.26.1		  2025-05-06			   GPSRINEX(1)